gio: Fix various implicit conversions from size_t to smaller types

Basically various trivial instances of the following MSVC compiler
warning:
```
../gio/gio-tool-set.c(50): warning C4267: '=': conversion from 'size_t' to 'int', possible loss of data
```

Signed-off-by: Philip Withnall <pwithnall@gnome.org>

gio/gapplicationcommandline.c

@@ -666,8 +666,8 @@ const gchar *
 g_application_command_line_getenv (GApplicationCommandLine *cmdline,
                                    const gchar             *name)
 {
-  gint length = strlen (name);
-  gint i;
+  size_t length = strlen (name);
+  size_t i;
 
   /* TODO: expand on windows */
   if (cmdline->priv->environ)

gio/gdbus-tool.c

@@ -1373,7 +1373,7 @@ dump_method (const GDBusMethodInfo *o,
 {
   guint n;
   guint m;
-  guint name_len;
+  size_t name_len;
   guint total_num_args;
 
   for (n = 0; o->annotations != NULL && o->annotations[n] != NULL; n++)

gio/gdbusconnection.c

@@ -3822,8 +3822,8 @@ static gboolean
 namespace_rule_matches (const gchar *namespace,
                         const gchar *name)
 {
-  gint len_namespace;
-  gint len_name;
+  size_t len_namespace;
+  size_t len_name;
 
   len_namespace = strlen (namespace);
   len_name = strlen (name);
@@ -3841,7 +3841,7 @@ static gboolean
 path_rule_matches (const gchar *path_a,
                    const gchar *path_b)
 {
-  gint len_a, len_b;
+  size_t len_a, len_b;
 
   len_a = strlen (path_a);
   len_b = strlen (path_b);

gio/gdbusdaemon.c

@@ -543,7 +543,8 @@ match_matches (GDBusDaemon *daemon,
 {
   MatchElement *element;
   Name *name;
-  int i, len, len2;
+  int i;
+  size_t len, len2;
   const char *value;
   int check_type;
 

gio/gdbusmessage.c

@@ -2852,7 +2852,7 @@ append_value_to_blob (GVariant            *value,
               const gchar *signature;
               child = g_variant_get_child_value (value, 0);
               signature = g_variant_get_type_string (child);
-              g_memory_buffer_put_byte (mbuf, strlen (signature));
+              g_memory_buffer_put_byte (mbuf, (guint8) strlen (signature));  /* signature is already validated to be this short */
               g_memory_buffer_put_string (mbuf, signature);
               g_memory_buffer_put_byte (mbuf, '\0');
               if (!append_value_to_blob (child,

gio/gdbusutils.c

@@ -113,7 +113,7 @@ is_valid_name (const gchar *start,
 gboolean
 g_dbus_is_name (const gchar *string)
 {
-  guint len;
+  size_t len;
   gboolean ret;
   const gchar *s;
 

gio/gdummyfile.c

@@ -239,7 +239,7 @@ static const char *
 match_prefix (const char *path, 
               const char *prefix)
 {
-  int prefix_len;
+  size_t prefix_len;
 
   prefix_len = strlen (prefix);
   if (strncmp (path, prefix, prefix_len) != 0)

gio/gfilenamecompleter.c

@@ -345,7 +345,7 @@ init_completion (GFilenameCompleter *completer,
   GFile *file, *parent;
   char *basename;
   char *t;
-  int len;
+  size_t len;
 
   *basename_out = NULL;
   

gio/gio-tool-mount.c

@@ -89,7 +89,7 @@ prompt_for (const char *prompt, const char *default_value, gboolean echo)
   gboolean restore_flags;
 #endif
   char data[256];
-  int len;
+  size_t len;
 
   if (default_value && *default_value != 0)
     g_print ("%s [%s]: ", prompt, default_value);

gio/gio-tool-set.c

@@ -42,10 +42,10 @@ static const GOptionEntry entries[] = {
 static char *
 hex_unescape (const char *str)
 {
-  int i;
+  size_t i;
   char *unescaped_str, *p;
   unsigned char c;
-  int len;
+  size_t len;
 
   len = strlen (str);
   unescaped_str = g_malloc (len + 1);

gio/glib-compile-schemas.c

@@ -680,7 +680,7 @@ key_state_serialise (KeyState *state)
 
               if (state->l10n_context)
                 {
-                  gint len;
+                  size_t len;
 
                   /* Contextified messages are supported by prepending
                    * the context, followed by '\004' to the start of the

gio/glocalfile.c

@@ -479,7 +479,7 @@ static const char *
 match_prefix (const char *path, 
               const char *prefix)
 {
-  int prefix_len;
+  size_t prefix_len;
 
   prefix_len = strlen (prefix);
   if (strncmp (path, prefix, prefix_len) != 0)

gio/gresource-tool.c

@@ -83,7 +83,7 @@ list_resource (GResource   *resource,
   gint i;
   gchar *child;
   GError *error = NULL;
-  gint len;
+  size_t len;
 
   children = g_resource_enumerate_children (resource, path, 0, &error);
   if (error)

gio/gresource.c

@@ -352,7 +352,7 @@ g_resource_find_overlay (const gchar    *path,
   /* This is a null-terminated array of replacement strings (with '=' inside) */
   static const gchar * const *overlay_dirs;
   gboolean res = FALSE;
-  gint path_len = -1;
+  size_t path_len = 0;
   gint i;
 
   /* We try to be very fast in case there are no overlays.  Otherwise,
@@ -449,9 +449,9 @@ g_resource_find_overlay (const gchar    *path,
   for (i = 0; overlay_dirs[i]; i++)
     {
       const gchar *src;
-      gint src_len;
+      size_t src_len;
       const gchar *dst;
-      gint dst_len;
+      size_t dst_len;
       gchar *candidate;
 
       {
@@ -466,7 +466,7 @@ g_resource_find_overlay (const gchar    *path,
         /* hold off on dst_len because we will probably fail the checks below */
       }
 
-      if (path_len == -1)
+      if (i == 0)
         path_len = strlen (path);
 
       /* The entire path is too short to match the source */

gio/gresourcefile.c

@@ -354,7 +354,7 @@ static const char *
 match_prefix (const char *path,
 	      const char *prefix)
 {
-  int prefix_len;
+  size_t prefix_len;
 
   prefix_len = strlen (prefix);
   if (strncmp (path, prefix, prefix_len) != 0)

gio/gunixsocketaddress.c

@@ -472,15 +472,21 @@ g_unix_socket_address_new_with_type (const gchar            *path,
 {
   GSocketAddress *address;
   GByteArray *array;
+  size_t path_len_unsigned;
 
   if (type == G_UNIX_SOCKET_ADDRESS_ANONYMOUS)
-    path_len = 0;
-  else if (path_len == -1)
-    path_len = strlen (path);
+    path_len_unsigned = 0;
+  else if (path_len < 0)
+    path_len_unsigned = strlen (path);
+  else
+    path_len_unsigned = (size_t) path_len;
 
-  array = g_byte_array_sized_new (path_len);
+  /* The code below can’t handle anything longer. */
+  g_return_val_if_fail (path_len_unsigned <= G_MAXUINT, NULL);
 
-  g_byte_array_append (array, (guint8 *)path, path_len);
+  array = g_byte_array_sized_new (path_len_unsigned);
+
+  g_byte_array_append (array, (guint8 *)path, path_len_unsigned);
 
   address = g_object_new (G_TYPE_UNIX_SOCKET_ADDRESS,
 			  "path-as-array", array,

gio/tests/data-output-stream.c

@@ -63,7 +63,7 @@ test_read_lines (GDataStreamNewlineType newline_type)
   GError *error = NULL;
   gpointer data;
   char *lines;
-  int size;
+  size_t size;
   int i;
 
 #define TEST_STRING	"some_text"
@@ -99,7 +99,7 @@ test_read_lines (GDataStreamNewlineType newline_type)
   
   /*  compare data */
   size = strlen (data);
-  g_assert_cmpint (size, <, MAX_LINES_BUFF);
+  g_assert_cmpuint (size, <, MAX_LINES_BUFF);
   g_assert_cmpstr ((char*)data, ==, lines);
   
   g_object_unref (base_stream);

gio/tests/task.c

@@ -1470,7 +1470,7 @@ test_run_in_thread_overflow (void)
   GCancellable *cancellable;
   GTask *task;
   gchar buf[NUM_OVERFLOW_TASKS + 1];
-  gint i;
+  size_t i;
 
   /* Queue way too many tasks and then sleep for a bit. The first 10
    * tasks will be dispatched to threads and will then block on
@@ -1516,13 +1516,13 @@ test_run_in_thread_overflow (void)
    * plausibly get (and we hope that if gtask is actually broken then
    * it will exceed those limits).
    */
-  g_assert_cmpint (i, >=, 10);
+  g_assert_cmpuint (i, >=, 10);
   if (g_test_slow ())
-    g_assert_cmpint (i, <, 50);
+    g_assert_cmpuint (i, <, 50);
   else
-    g_assert_cmpint (i, <, 20);
+    g_assert_cmpuint (i, <, 20);
 
-  g_assert_cmpint (i + strspn (buf + i, "X"), ==, NUM_OVERFLOW_TASKS);
+  g_assert_cmpuint (i + strspn (buf + i, "X"), ==, NUM_OVERFLOW_TASKS);
 }
 
 /* test_return_on_cancel */

gio/win32/gwin32fsmonitorutils.c

@@ -160,8 +160,8 @@ g_win32_fs_monitor_callback (DWORD        error,
 
           if (monitor->isfile)
             {
-              gint long_filename_length = wcslen (monitor->wfilename_long);
-              gint short_filename_length = wcslen (monitor->wfilename_short);
+              size_t long_filename_length = wcslen (monitor->wfilename_long);
+              size_t short_filename_length = wcslen (monitor->wfilename_short);
               enum GWin32FileMonitorFileAlias alias_state;
 
               /* If monitoring a file, check that the changed file

gio/win32/gwinhttpfile.c

@@ -318,7 +318,7 @@ static const char *
 match_prefix (const char *path,
               const char *prefix)
 {
-  int prefix_len;
+  size_t prefix_len;
 
   prefix_len = strlen (prefix);
   if (strncmp (path, prefix, prefix_len) != 0)